Four franchises clearly stand out from the rest of the Frontier League pack. The RiverHawks finished second to Gateway in the division race in 2003 and missed the playoffs. The following year, Rockford won the division and beat the defending league champ Grizzlies in a five-game slugfest in the first round of the playoffs en route to the pennant.

September meetings with the Evansville Otters have represented the high and low point of the team's postseason history. The RiverHawks swept the Otters in the 2004 finals. Two years later, the RiverHawks lost a 2-0 series lead in the first round and a ninth-inning lead in the deciding fifth game. The Otters, who had a losing regular-season record, pulled a huge upset of Rockford en route to the 2006 pennant.

Kalamazoo is perhaps an underappreciated rivalry, though it goes back to the early days. In 2002, the RiverHawks' first year in town, they were forced to watch the out-of-town scoreboard in a race with Kalamazoo for the final playoff spot. The Kings clinched on the next-to-last day of the season. Three years later, the Kings and RiverHawks met in the first round of the playoffs. Rockford took Game 1 in Kalamazoo, but the Kings won the next three to dethrone the RiverHawks. In 2007, the teams met in an epic four-day, seven-game, split-site series to determine the last postseason berth. The RiverHawks won three straight games, two in walkoff fashion, in which they faced mathematical elimination, and won the wild card.

Last year, Windy City went from perennial bottom feeder to champion. Known as the Cook County Cheetahs in 2002, they took two of three from the RiverHawks to spoil Rockford's playoff push. That was the last time Windy City mattered at the end of the season, until 2007. The ThunderBolts led the division wire to wire and went a league-record 68-28. They swept the RiverHawks in the first round of the playoffs.